Sulfonic acid esters and quaternary salts of polyhydroxy compounds containing 3 or more ethylene oxide chains as novel photographic sensitizers



SULFQNIC ACID ESTERS AND QUA'IERNARE Z SALTS F PQLYHYDRDXY COMPOUNDS COlN- TAHNING 3 OR MORE ETHYLENE OXIDE CHAINS AS NOVEL PHOTOGRAPHIC SENSI- TIZERS Dorothy J. Beavers, Rochester, N.Y., amlgnor to Eastman Kodak Company, Rochester, N.Y., a corporation 1? New Jersey gin Drawing. Filed Nov. 16, 1959, Ser. No. 853,009v 9 Claims. (Cl. 969-108) This invention relates to photographic silver halide emulsions, and more particularly, to an improved means for sensitizing such photographic silver halide emulsions,

A number of methods have been previously described for increasing the sensitivity of photographic silver halide emulsions other than methods of optical or spectral sensitization which involve the incorporation of certam color compounds or dyes in the emulsions. The incorporation of such dyes in the emulsions increases or extends the optical range of sensitivity and for this reason. such dyes are commonly referred to as optical or spectral sensitizing dyes. It is also well known to increase the sensitivity of photographic emulsions by the addition of sulfur compounds capable of reacting with silver salts to form silver sulfide, or with reducing agents (compounds of these types are also naturally present in gelatin) or with salts of gold or other noble metals, or with combinations of two or more of the aforementioned compounds generally known as chemical sensitizers. Such chemical sensitizers are believed to react with the silver halide to form, on the surface of the silver halide minute amounts of silver sulfide or of silver or of other noble metals, and these processes are capable of increasing the sensitivity of developing-out emulsions by a very large factor. However, there is a definite limit beyond which further additions of chemical sensitizers or of further digestion with the sensitizer present, merely increases fog of the photog-raphic emulsion with constant or decreasing emulsion speed.

I have now found a means of further increasing the sensitivity of photographic emulsions which may be applied even though the ordinary processes of chemical sensitization have been carried to the efiective limit of the photographic emulsion in question. My process is to be distinguished from hypersensitization which is produced by bathing a finished coating with water or with solutions of ammonia, amines or silver salts. Such processes act primarilyon optically sensitized photographic emulsions and tend to increase the free silver ion concentration of the emulsion and greatly diminish its stability. My process is also to be distinguished =from hypersensit1zat1on by mercury vapor which gives a transitory efiect that is lost on storage of the film. The compounds used 1n my invention do not appear to be chemical sensitizers in the United States Patent 0 F 3,939,873 Patented June 19, 1962 ICC usual sense, since they increase speed by their presence during exposure and processing, and require no digestion with the photographic emulsions to produce an increase in speed nor does their chemistry indicate that they are likely to react with silver halideunder normal emulsion conditions.

The novel sensitizers of my invention, the sulfonic acid esters and quaternary salts of tertiary amine derivatives of the condensation products of alkylene oxides with compounds containing the pyranose ring system such as anhydrosorbital and disaccharide derivatives, are unique in that the eifects produced are additive in photographic emulsions which have already been sensitized to their optimum or near optimum with conventional chemical sensitizers, such as labile sulfur compounds. The novel sensitizers of my invention, however, can be used to sensitize photographic silver halide emulsions containing no other sensitizers if desired. The novel sensitizers of my invention are not strictly chemical sensitizers since chemical sensitizers do not generally provide the additive elfects of the type mentioned. It is therefore an object of my invention to provide photographic silver halide emulsions which have been sensitized with polyhydroxy compounds containing three or more ethylene oxide chains, their sulfonic acid esters and their polyquaternary salts.

It is a further object of'my invention to increase the sensitivity of ordinary photographic silver halide emul sionswhich have been sensitized with chemical sensitizers, such as compounds containing labile sulfur atoms or goldcontaining compounds without increases in fog which might seriously effect the usefulness of the emulsions.

A further object is to provide a novel class of sensitizers which disperse readily in emulsion dispersions.

A still further object is to provide a novel class of sensitizers which when added to silver halide photographic emulsions, produce their sensitizing effects without requiring further digestion of the emulsion.

Other objects will become apparent from the following description and examples.

According to my invention I have found that the sensitivity of ordinary high speed silver halide emulsions chemically sensitized in the conventional Way can be substantially increased by the incorporation of sulfonic acid esters and quaternary salts of tertiary amine derivatives of the condensation products of alkylene oxides with compounds containing the pyranose ring system such as anhydrosorbitol or disaccharide derivatives.

The sulfonic acid esters and quaternary salts of tertiary amine derivatives of the condensation products of alkylene oxides and these pyranose ring compounds of my invention are particularly useful since they have a rather high degree of water solubility and are easily incorporated in conventional photographic silver halide emulsions in sensitizing amounts.

Included in the compounds of my invention are those having the following general formula:

4 represented by Z Z Z Z Z Z Z Z has a total of from 8 to 680; R represents a hydroxy substituted polymethylene chain having from 2 to 4 carbon atoms; at is from 1 to 2; X is a lower alkyl sulfonate radical 5 such as methylsulfonate, ethylsulfonate, propylsulfonate I and butylsulfonate, etc., an arene sulfonate radical such 0112032) TX as p-toluenesulfonate, a pyridinium group or an ammonium group; Y is an anion such as the lower alkyl sulfonate X'WHZCHZOHTH ions, methylsulfonate, ethylsulfonate, propylsulfonate, 19 butylsulfonate, etc., an arene sulfonate ion, a perchlorate H 1(GH; m,-CH,, ion, or a halide ion such as chloride, bromide, and iodide; and m is 1 when X is a sulfonate radical and m is 2 when X is a pyridinium radical or an ammonium radical.

Compounds of Formula II in which from 1 to of v the Z groups as defined above are replaced by a wherein m and m are mtegers from 1 to 18 and the sum of m-l-m is from 4 to 20; d is 1 or 2, n H and n each represent a positive integer of at. least 1, such that the H sum of'n +n and n is from 8 to 680; and X is a sulfonic C(CH2) )d-! 2)q" 3 ester radical, a pyridinium radical, or an ammonium radi- 2O cal and corn ounds havin the eneral formula:

p g g group in which q and q are positive integers from 1 to 18 and the sum of q+q' is from 10 to 20, and d is from 1 to 2, also have a sensitizing efi'ect on silver halide emul- 11 0-2, 5 sions. I I l 2 The molecular weight of compounds of my invention can vary over rather wide ranges primarily because of Zfi'O-C CHCHzO- s the difierent numbers of ethylene oxide units that they may have per molecule. Compounds of Formula I have three chains containing one or more ethylene oxide units I per chain while compounds of Formula 11 have eight chains containing one or more ethylene oxide units per chain. These ethylene oxide chains on a given molecule ZPO-C may be of equal or varying lengths. The sensitizing compounds of my invention have molecules with a total of r- 2 from 8 to 680 ethylene oxide units per molecule. The total molecular weight of the ethylene oxide units in a molecule may thus vary from 350 to about 30,000. The preferred compounds of my invention have a total of from 20 to 460 ethylene oxide units per molecule. In these wherein the Zs represent a compounds the range of molecular weight of the total ethylene oxide units per mole varies from 880 to 20,240. Typical examples that illustrate compounds of my in- R(OCHZCHZ)D R vention that have structures described by Formula I are given in Table I. -This table gives the names of the group; R represents a methyl substituted methylene chain compounds and describes their structures by indicating having from 2 to 6 carbon atoms; n is a positive integer the groups represented by X and the values of m-l-m of at least 1 such that the sum of the ns in the groups and of d.

TABLE I Com- The The pound Name X of Formula I represents sum of value of N o. m-l-m; d is 1 Poly(oxyethylene)sorbitan monolaurate tris(methanesulfonate) -0SO2CH; 10 1 2 Poly(oxyethylene)sorbitan monostearate tris(2-methyl-5-ethyl pyridlnium N/ OH3SO3 16 1 rnethanesulfonate) 3 .l Poly(oxyethylene)sorbitan monolaurate tris(pyridlniurn methanesultonate) CH3S03- 10 1 +CHa 4 Poly(oxyethylene)sorbltan monolaurate tris (dimethyl-fl-hydroxyethylammonlum -NOH:CH;OH CHaSO 10 1 methanesulfonate).

5 Polykzxyethylenwsorbltan monolaurate tris(triethylammonium methanesul- N(G2 s)S CH3SO3 l0 1 0118. 6 6 Poly(oxyethylene)sorbitan monostearate tris(pyridinium methanesulfonate) l\ OH3SO3- 16 1 7 Poly(oxyethylenejsorbitan inonostearate tris(methanesulfonate) OS0 CH 16 1 Typical examples illustrating compounds of my invention that have structures described by Formula II are given in Table II. This table gives the names of the compounds and describes their structure by indicating the groups represented by X, Y, Z, and the sum of all the ns in compounds of Formula 11:

6 C. While stirring, 17.1 grams of methanesulfonyl chloride was added dropwise at 0 to 10 C. The mixture in which some pyridine hydrochloride had separated, was stirred for 2 hours at this temperature and then allowed 5 to come to room temperature (2 hours). it was chilled, acidified with hydrochloric acid (1:1) and then saturated TABLE II Total Corn- Z value pound Name (R(OCH1CH=) n 'd-IXYm-l) of Formula II represents of ns of No. Formula t 8 Sucrose octakis-[Z-methylethylpolflowethyl)meth- CHg-CH(O CH2C 2)n-OSO2CH3 30 anesuL onate] (The oxyethylene groups of this compound have a total molecular weight of 1320). (3H 9 Sucrose octakis-[Z-methylethylpoly(oxyethyDpyri- CHq-OH-(O CH2CHI)niI 01160; 30

dim'um methanesulfonate] (The oxyethylene groups of this compound have a total molecular weight of 1320). (3H 10 Sucrose octakis-[Z-methylethyl poly(oxyethyl) CHz-CH-(O CH2CH2)n I(C2H6)B 05 80;

triethylammonium methanesulionate] (The oxyethylene groups of this compound have a total molecular weight of 1320). (3H 11. Sucrose octakls-[Z-methylethyl poly(oxyethyl)meth- -OH CH(O CHzOHi) 11-0 S O2CH3 anesulionate] (The oxyethylene groups of this compound have a total molecular weight of 3080) (IJHQ 12. Sucrose octakis-[Z-methylethyl poly(oxyethyl) -OHrCH-(O CH:CH2)D-N CHaSO; 70

pyridinium methanesulfonate] (The oxyethylene groups of this compound have a total molecular Weight of 3080). (111 (')H 13 Sucrose octakis-[2-methy1ethyl poly(oxyethyl)oxy- CHgCH-(OCHzCHg) 0CH1-CH-OHr-N C104 30 2-hydroxypropy1-3-pyridinium perchlorate] (The oxyethylene groups of this compound have a total molecular weight of 1320). CH; C| H 14--- Sucrose octakis-[2-methylethyl poly(oxyethyl)oxy- -CH (iH(0CH OE ),;OCHZCH-OH N C10; 70

2-hydroxypropyl-3-pyrioinium perchlorate] (The oxyethylene groups of this compound have a total molecular weight 013080).

The general method of preparation of these polyhydroxy compounds containing three or more ethylene oxide chains can be illustrated as follows. Anhydrosorbitols can be easily acylated with one or several moles of a long-chain acid halide by the Schotten-Baumann procedure. Esterification techniques such as the use of a fatty acid and polyhydroxy compound in the presence of an acid catalyst and a solvent such as toluene to help azeotrope ed the water will also give the desired mono or diacylate starting polyhydroxy derivatives.

The acylated polyhydroxy compound, or if desired the unacylated polyhydroxy compound, can be reacted directly with epoxides at 60 C. or above by the use of an acid catalyst, a Lewis acid-type catalyst such as borontrifluoride or a basic catalyst such as sodium hydroxide or triethylamine. The ratio of the ethylene oxide molecules to the polyhydroxy molecule can be easily controlled. The ethylene oxide may add to one or all of the free hydroxy groups in equal or varying chain lengths.

The polyquaternary derivatives are prepared by dissolving the polyhydroxy polyethylene oxide products in cold pyridine and esterifying the w-hydroxy groups with benzene, p-toluene, or methanesulfonyl chloride. The polyesters are converted to the polyquaternary derivatives by reacting with tertiary bases such as trialkylamines or heterocyclic compounds such as pyridine.

The following examples will serve to illustrate the specific method of preparing various compounds of the invention useful in practicing my invention.

Example I Poly(oxyerhylene)sorbitan monolaurate tris(methaneszllfonate).45.2 grams of poly(oxyethylene) sorbitan monolaurate dried by dissolving in benzene, azeotroping oi the Water and then removing the benzene, was dissolved in 150 ml. of pyridine and the solution chilled to Example II Poly(oxyethylene)sorbitan monosteamte tris(2-metlzyl- 5-ethylpyridinium methanesulf0nate).-A mixture of 3 parts of poly(oxyethylene)sorbitan monostearate tris- (methanesulfonate) prepared in the same manner as was used in Example I excepting that poly(oxyethylene)sorbitan monostearate was used inplace of the corresponding monolaurate, and 5 parts of 5-ethyi-2-methylpyridine Was heated for 5 hours at C. The mixture was cooled and shaken vigorously with 30 of ether. The oily layer was separated from the ether wash and the washing repeated 3 times with fresh ether. The last traces of ether were removed under reduced pressure. Two parts or" a 60 dark colored oil remained.

Example III P0ly(0xyethylene)sorbitczn monolaurate trz's(pyridinium methanesulfonate).This compound was prepared by the same procedure used in Example 11 by using the molar equivalent amount of poly(oxyethylene)sorbitan monolaurate in place of the corresponding monostearate, and pyridine in place of Z-methyl-S-ethyl pyridine.

Example IV Poly(0xyethylene)s0rbitan monolaurate tris(dimethyl- B-hydroxyethylammonium methanesulfonate).-Po1y(oxyethylene)sorbitan monolaurate tris(methanesulfonate), 4 parts, was heated for 15 hours at C. with 10 parts of dimethylaminornethanol. he excess amine was re- 75 moved under reduced pressure and the residue washed 4 times with 25 ml. portions of ether. The last traces of ether were removed under reduced pressure. Two parts of a very dark, viscous oil remained. Decolorizing carbons were inefiective.

Example V Poly(oxyethylene)sorbitan mouolaurate tris(triethylammonium metlzanesulfonate).-To a mixture of parts 7 Example VI Poly(oxyethylene)sorbitan monostearate tris(pyridinium mezhanesulfonate) .-This compound was prepared by the same procedure as described in Example III by using the molar equivalent amount of poly(oxyethylene) sorbitan monostearate in place of the corresponding monolaurate.

Example V11 Poly(oxyerhylene)sorbitan monostearate tris(methanesulf0nate).This compound was prepared by the same procedure described in Example I by using the molar equivalent amount of poly(oxyethylene)sorbitan monostearate in place of the corresponding monolaurate.

Example VIII I Sucrose octakis [Z-methylethyl poly(oxyethyl) methanesulfonate] in which the oxyethylene groups of each molecule have a total molecular weight of 1320.

Octakis-(Z-hydroxypropyl)sucrose, 48 grams 0.06 mole), and 3 drops of a boron-trifluoride-etherate catalyst were heated to 95 C. with stirring in an apparatus equipped with a Dry Ice acetone cooled condenser. Ethylene oxide was bubbled below the surface of the viscous liquid rapidly enough to give vigorous refluxing. After 4 hours, the volume of the product had about doubled and become more fluid. The flask was placed under vacuum at a temperature of 100 C. for /2 hour to remove unreacted ethylene oxide or dioxane. 78 grams of ethylene oxide (30 molar equivalents) per mole of sucrose had reacted to produce sucrose octakis-[Z-methylethoxypropyl- (ethoxy)ethyl alcohol], a Water-soluble, dark orange, viscous compound having oxyethylene groups with a total molecular weight of 1320 per molecule.

37.3 grams (0.017 mole) of the above product was dissolved in 300 ml. of dry pyridine. The flask and contents Were cooled to 0 C. and with vigorous stirring, 16.2 grams (0.14 mole) of methane sulfonyl chloride was added while keeping the temperature below 0 C. for 2 hours, then the mixture was stirred for 2 hours at room temperature. The white slurry was acidified at C. with 1:1 hydrochloric acid, the solution saturated with sodium chloride, and the product extracted 3 times with 200 ml. portions of warm benzene. The benzene extracts were dried over sodium sulfate overnight, filtered, and concentrated on steam bath under vacuum. The prodnet (32 grams) was isolated as a pale yellow slightly water-soluble, viscous oil.

Example IX vacuum on the steam bath until only a viscous oil remained, It was dissolved in m1. of methanol and the 55 oil precipitated outwith 50ml. of anhydrous ether. The ether was decanted from the oil and the precipitation repeated until no pyridine odor remained. Traces of ether were removed on the steam bath under vacuum leaving 9.1 grams of an orange-colored, viscous, water-soluble oil.

Example X Sucrose octakis-[2-mezhylethyl poly(oxyethyl)triethylammonium methanesuljonate], in which the oxyethylene groups of each molecule have a total molecular weight of 1320.

To 5 parts of sucrose octakis-[Z-methylethyl poly(oxyethyl) methanesulfonate], prepared as described in Example VIII, was added 15 parts of triethylamine. The mixture was heated at the boiling point for 15 hours and the excess amine removed,'first by decantation and iiinally by washing 4 times with small volumes of ether. The last traces of ether were removed by heating on a steam bath. There remained 5.5 parts of a viscous oil.

Example XI Surcrose octakis-[Z-methylethyl poly(oxyethyl)metlzane-sulfonate] in which the oxyethylene groups of each molecule have a total molecular Weight of 3080.

This compound was prepared by the same procedure as was described in Example Vill excepting that process of adding ethylene oxide and catalyst described in paragraph 1 (Example VH1) was continued until a total of 70 molar equivalents of ethylene oxide had reacted with the octakis (2-hydroxypropy-l)sucrose to produce sucrose octakis-[Z-rnethylethyl poly(oxyethyl)] having oxyethylene groups with a total molecular weight of 3080 per molecule before the process of paragraph 2 (Example VII-I) was performed.

Example XII was used in Example IX by using the molar equivalent amount of the corresponding sucrose octakis derivative in which the oxyethylene groups of each molecule had a total molecular weight of 3080 instead of 1320.

Example XIII Sucrose oczakis-[Z-methylezhyl poly(oxyethyl)oxy-2- hydroxy-propyl-3-pylidinium perchlorate], in which the oxyethylene groups of each molecule have a total molecular weight of 1320. p i

14.6 grams (about 0.007 mole) of sucrose octakis-[2 methylethoxy poly(ethoxy)ethyl alcohol], in which the oxyethylene groups of each molecule had total molecular weight of 1320 was added to a ml. flask equipped with stirrer and condenser. Three drops of borontrifluoride catalyst were added to the syrup, followed by 5.2 grams (0.056 mole) of epichlorohydrin at room temperature. The syrup was heated for 1 hour on the steam bath, then 3 hours at 60 C. Upon further heating of the syrup under vacuum on the steam bath for an hour to remove unreacted epichlorohydrin, a dark, viscous oil weighting 18.6 grams was obtained.

The dark syrup was dissolved in methanol, treated with activated carbon powder (Darco) and diatomaceous earth (Hyflo) and heated for 1 hour on a steam bath. The mixture was allowed to stand overnight, heated, filtered through a diatomaceous earth (Hyflo) filter cake and the orange-yellow solution concentrated. A yield of 17.3 grams of sucrose octakis-[2-methylethyl poly (oxyethyl)oxy-2-hydroxy-3-chloropropane)], a viscous, yellow oil was obtained.

10 grams (about 0.0035 mole) of the product prepared immediately above was refluxed vigorously with 50 ml. of anhydrous pyridine for 4 hours and the excess pyridine 9 removed under vacuum. The oil was slurried with dry ether, allowed to settle, chilled and the ether decanted. This step was repeated several times until no pyridine odor remained and the ether traces were removed under vacuum, leaving 10.7 grams (88%) of a dark, orangecolored, viscous syrup.

The above pyridinium salt was dissolved in 50 ml. of ethanol and added to a solution of 3.4 grams of sodium perchlorate monohydrate (no excess) in 50 ml. of acetone. The solution began precipitating sodium chloride immediately. After concentrating the solution continuously on the steam bath (bumping) the precipitated salt was filtered. The concentrated solution was then concentrated to dryness, leaving a turbid orange syrup. The syrup was redissolved in 30 ml. of dry acetone, gravity filtered and concentrated under vacuum, giving 11.1 grams (90%) of a dark orange-colored, viscous syrup.

This sucrose salt. probably consists of a mixture ofv sugar pyridinium salts in which the oxyethylene chains may vary in size in each hydroxyl group, and where not all the chains may have been converted to pyridinium salt derivatives, giving for exmple, 5, 6 or 7 quaternary groups per sucrose unit.

Example X1 Sucrose oczakis-[Z-methylethyl ply(oxyethyl)0xy-2- hydr0xy-pr0pyl-3-pyridinium perchl0mte)], in which the oxyethylene groups of each molecule hav a total molecular Weight of 3080.

This compound was prepared by the same procedure as was used in Example XIII by using the corresponding sucrose octakis-[Z-methylethoxy poly(ethoxy)ethyl alcohol] in which the oxyethyleue groups of each molecule had a total molecular weight of 3080 instead of 1320.

The above examples are merely illustrative and it is to be understood that other compounds can be prepared and used according to the invention as described herein.

The compounds of my invention are added to ordinary photographic silver halide emulsions for the purpose of increasing the sensitivity thereof as has been indicate above.

The preparation of photographic silver halide emulsions involves three separate operations:.

(1) Emulsification and digestion of silver halide,

(2) The freeing of the emulsion of excess water soluble salts usually by washing with Water, and

(3) The second digestion or after-ripening to obtain increased emulsion speed or sensitivity.

[Mess The theory of the Photographic Process, 1954]. The sensitizers of my invention can be added to the emul- .sion before the final digestion or after-ripening or they can be added immediately prior to coating. My new photographic sensitizers are characterized by not requiring any final digestion or after-ripening in order to obtain optimum sensitivity.

The particular quantity of the sulfonic acid esters or quaternary salts of tertiary amine derivatives of the con densation products of allrylene ox de and pyranose ring products of my invention used in a given emulsion, can vary depending upon the effects desired, degree of ripening, silver content of the emulsion, etc. The amount used is also dependent upon the particular stage at which the sensitizer is added during the preparation of the emulsion. I have found that generally from about 50 mg. to about 5 g. of my compound per mole of silver halide are quite adequate to accomplish the desired sensitization.

My sensitizer can be added to photographic emulsions using any of the well known techniques in emulsion making. Generally these compounds are soluble enough in water so that the concentration needed may be readily obtained. Most of the compounds are water soluble viscous oils. The compounds can be dissolved in a suitable solvent other than water if necessary and added to 10 the silver halide emulsion or they can be added to the emulsion in the form of a dispersion by techniques similar to those used to incorporate certain types of color f rming compounds [couplers] in a photographic emulsion. Techniques of this type are described in Jelley et al. U.S. Patent 2,322,027, issued June 15, 1943, and Fierke et al. U.S. Patent 2,801,171, issued July 30, 1957. As indicated above, the solvent should be selected so that it has no harmful efiect upon the emulsion. Generally solvents or diluents which are miscible with water are to be preferred. In instances where water alone is not satisfactory for dissolving my sensitizing compounds, solvents such as ethanol, acetone, pyridine, N,N-dimethyl formamide, etc. can be used and this solution added to the emulsion. If desired certain of my compounds can be prepared in finely divided form by dispersion in water alone or in the presence of a suitable dispersing agent and added to the emulsion in this form. It is quite apparent that the compounds of my invention should be dispersed suliiciently in water so thatthey can be adsorbed on the grains of the silver halide present in the emulsion in suflicient amount to sensitize the emulsion. It is apparent that the optimum amount for each of the compounds will vary somewhat from emulsion to emulsion and from sensitizer to sensitizer. The optimum amount'for any given sensitizer can be determined for any particular emulsion by making a series of tests in which the quantity or" my sensitizer-is varied over a given range. Exposure of the treated emulsion in a conventional photographic testing apparatus such as an intensity scale sensitometer, followed by development, and image density measurement, will reveal the most advantageous concentrations for that sensitizer in that particular emulsion. Such matters are well understood by those skilled in the art.

The photographic emulsions used in practicing our invention are of the developing-out type.

The emulsions can be chemically sensitized by any of the accepted procedures. The emulsions can be digested with naturally active gelatin, or sulfur compounds can be added such as those described in Sheppard U.S. Patent 1,574,944, issued March 2, 1926, Sheppard et al. U.S. Patent 1,623,499, issued April 5, 1927, and Sheppard et al. U.S. Patent 2,410,689, issued November 5, 1946.

The emulsions can also be treated with salts of the noble metals such as ruthenium, rhodium, palladium, iridium, and platinum. Representative compounds are ammonium chloropalladate, potassium chloroplatinate, and sodium chloropalladite, which are used fog sensitizing in amounts below that which produces any substantial fog inhibition, as described in Smith and Trivelli U.S. Patent 2,448,060, issued August 31, 1948, and as.

antiioggants in higher amounts, as described in Trivelli and Smith U.S. Patents 2,566,245, issued August 28, 1951 and 2,566,263, issued August 28, 1951.

The emulsions can also be chemically sensitized with gold salts as described in Waller et al. U.S. Patent 2,399,083, issued April 23, 1946, or stabilized with gold salts as descfibed in Damschroder U.S. Patent 2,597,856,

'ssued May 27, 1952, and Yutzy and Leermakers U.S. atent 2,597,915, issued May 27, 1952. Suitable comounds are potassium chloroaurite, potassium aurithio- ,anate, potassium chloroaurate, auric trichloride and urosulfobenzothiazole methochloride.

The emulsions can also be chemically sensitized with reducing agents such as stannous salts (Carroll U.S. Patent 2,487,850, issued November 15, 1949), polyamines; such as diethyl triaznine (Lowe and Jones U.S. Patent 2,518,698,'issued August 15, 1950), polyamines, such as spermine (Lowe and Allen U.S. Patent 2,521,925, issued September 12, 1950), or bis(;3-aminoethyl) sulfide and its water-soluble salts (Lowe and Jones U.S. Patent 2,521,926, issued September 12, 1950).

The emulsions can also be optically sensitized with ll cyanine and merocyanine dyes, such as those described in Brooker U.S. Patents 1,846,301, issued February 23, 1932; 1,846,302, issued February 23, 1932; and 1,942,854, issued January 9, 1934; White U.S. Patent 1,990,507, issued February 12, 1935; Brooker and White U.S. Patents-2,112,140, issued March 22, 1938; 2,165,338, issued July 11, 1939; 2,493,747, issued January 10, 1950, and 2,739,964, issued March 27, 1956; Brooker and Keyes U.S. Patent2,493,748, issued January 10, 1950; Sprague U.S. Patents 2,503,776, issued April 11, 1950, and 2,519,001, issued August 15, 1950; Heseltine and Brooker U.S. Patent 2,666,761, issued January 19, 1954; Heseltine U.S. Patent 2,734,900, issued February 14, 1956; Van Lare U.S. Patent 2,739,149, issued March 20, 1956; and Kodak Limited British Patent 450,958, accepted July 15, 1936.

The emulsions can also be stabilized with the mercury compounds of Allen, Byers and Murray U.S. Patent 2,728,663, issued December 27, 1955; Carroll and Murray U.S. Patent 2,728,664, issued December 27, 1955; and Leubner and Murray U.S. Patent 2,728,665, issued December 27, 1955 the triazoles of Heimbach and Kelly U.S. Patent 2,444,608, issued July 6, 1948; the azaindenes of Heimbach and Kelly U.S. Patents 2,444,605 and 2,444,606, issued July ",6, 1948; Heimbach U.S. Patents 2,444,607, issued July 6, 1948, and 2,450,397, issued September 28, 1948; Heimbach and Clark U.S. Patent 2,444,609, issued July 6, 1948; Allen and Reynolds U.S. Patents 2,713,541, issued July 19, 1955, and 2,743,181, issued April 24, 1956; Carroll'and Beach U.S. Patent 2,716,062, issued August 23, 1955; Allen and Beilfuss U.S. Patent 2,735,769, issued February 21, 1956; Reynolds and Sagal U.S. Patent 2,756,147, issued July 24, 1956; Allen and Sagura U. S. Patent 2,772,164, issued November 27, 1956, and those disclosed by Birr in Z. Wiss. Phot, vol. 47, 1952, pages 2-28; the disulfides of Kodak Belgian Patent 569,317, issued July 31, 1958; the

' quaternary benzothiazolium compounds of Brooker and Stand U. S. Patent 2,131,038, issued September 27, 1938, or the polymethylene bis-benzothiazolium salts of Allen and Wilson U.S. Patent 2,694,716, issued November 16, 1954 (e.g., decamethylene-bis-benzothiazolium perchlorate); or the zinc and cadmium salts of Jones U.S. Patent 2,839,405, issued June 17, 1958; and the carboxymethylrnercapto compounds of Murray, Reynolds and Van Allan U.S. Patent 2,819,965, issued January 14, 1958.

The emulsions may also contain speed increasing compounds of the quaternary ammonium type of Carroll U.S.' Patent 2,271,623, issued February 3, 1942; Carroll and Allen U.S. Patent 2,288,226, issued June 30, 1942;

and Carroll and Spence U.S. Patent 2,334,864, issued November 23, 1943; or the quaternary ammonium salts and polyethylene glycols of Piper U.S. Patent 2,886,437, issued May 12, 1959; and the polyethylene glycol type of Carroll and Beach U.S. Patent 2,708,162, issued May 10, 1955; or the thiopolymers of Graham and Sagal U.S. application Serial No. 779,839, filed December 12, 1958, or Dann and Chechak U.S. application Serial No. 779,874, filed December 12, 1958.

The emulsions may contain a suitable gelatin plasticizer such as' glycerin; a dihydroxy alkane such as 1,5-pentane diol as described in Milton and Murray U.S. application Serial No. 588,951, filed June 4, 1956, now U.S. Patent 2,960,404, issued November 15, 1960; an ester of an ethylene bis-glycolic acid such as ethylene bis(methyl glycolate) as described in Milton U.S. application Serial No. 662,564, filed May 31, 1957, now U.S. Patent 2,904,- 434, issued September 15, 1959; bis-(ethoxy diethylene glycol) succinate as described in Gray U.S. application Serial No. 604,333, filed August 16, 1956, now U.S. Patent 2,940,854, issued June 14, 1960, or a polymeric hydrosol as results from the emulsion polymerization of a mixture of an amide of an acid of the acrylic acid series,

12 an acrylic acid ester and a styrene-type compound as described in Tong U.S. Patent 2,852,386, issued September 16, 1958. The plasticizer may be added to the emulsion before or after the addition of a sensitizing dye, if used. The emulsions may be hardened with any suitable hardener for gelatin such as formaldehyde; a halogensubstituted aliphatic acid such as mucobromic acid as described in White U.S. Patent 2,080,019, issued May 11,

1937; a compound having a plurality of acid anhydride groups such as 7,8-diphenylbicyclo (2,2,2)-7-octene-2,3,5, 6-tetra-carboxylic dianhydride, or a dicarboxylic or a disulfonic acid chloride such as terephthaloyl chloride or naphthalene-LS-disulfonyl chloride as described in Allen and Carroll U.S. Patents 2,725,294, and 2,725,295, both issued November 29, 1955; a cyclic 1,2-diketone such as cyclopentane-l,2-dione as described in Allen and Byers U.S. Patent 2,725,305, issued November 29, 1955; a bisester of methane-sulfonic acid such as 1,2-di-(methanesulfonoxy) -ethane as described in Allen and Laakso U.S. Patent 2,726,162, issued December 6, 1955 1,3-dihydroxymethylbenzimidazol-Z-one as described in July, Knott and Pollak U.S. Patent 2,732,316, issued January 24, 1956; a dialdehyde or a sodium bisulfite derivative thereof, the aldehyde groups of which are separated by 2-3 carbon atoms, such as fi-methyl glutaraldehyde bis-sodium bisulfite as described in Allen and Burness U.S. patent application Serial No. 556,031, filed December 29, 1955; a his aziridine carboxamide such as trimethylene bis( l-aziridine carboxamide) as described in Allen and Webster U.S. patent application Serial No. 599,891, filed July 25, 6, now U.S. Patent 2,950,197, issued August 23, 1960; or 2,3-dihydroxy dioxane as described in Jeflreys U.S. Patent 2,870,013, issued January 20, 1959.

The emulsions may contain a coating aid such as sapomin; a lauryl or oleyl monoether of polyethylene glycol as described in Knox and Davis U.S. Patent 2,831,766, issued April 22, 1958; a salt of a sulfated and alkylated polyethylene glycol ether as described in Knox and Davis U.S. Patent 2,719,087, issued September 27, 1955; an acylated alkyl taurine such as the sodium salt of N-oleoyl- N-methyl taurine as described in Knox, Twardokus and Davis U.S. Patent 2,739,891, issued March 27, 1956; the reaction product of a dianhydride of tetracarboxybutane with an alcohol or an aliphatic amine containing from 8 to 18 carbon atoms which is treated with a base, for example, the sodium salt of the monoester of tetracarboxybutane as described in Knox, Stenberg and Wilson U.S. Patent 2,843,487, issued July 15, 1958; a watersoluble maleopimarate or a mixture of a water-soluble maleopimarate and a substituted glutamate salt as described in Knox and Fowler U.S. Patent 2,823,123, issued February 11, 1958; an alkali metal salt of a substituted amino acid such as disodium N-(carbo-p-tert. octylphenoxypentaethoxy) glutamate as described in Knox and Wilson U.S. patent application Serial No. 600,679, filed July 30, 1956; or a sulfosuccinamate such as tetrasodium N-(1,2-dicarboxyethyl)-N-octadecyl sulfosuccinamate or N-lauryl disodium sulfosuccinamate as described in Knox and Stenberg U.S. patent application Serial No. 691,125, filed October 21, 1957, now U.S. Patent 2,992,108, issued July 11, 1961.

The addenda which we have described may be used in various kinds of photographic emulsions. In addition to being useful in X-ray and other nonoptically sensitized emulsions they may also be used in orthochromatic, panchromatic, and infrared sensitive emulsions. They may be added to the emulsion before or after any sensitizing dyes which are used. Various silver salts may be used as the sensitive salt such as silver bromide, silver iodide, silver chloride, or mixed silver halides such as silver chlorobromide or silver bromoiodide. The agents may be used in emulsions intended for color photography, for example, emulsions containing color-forming couplers or emulsions to be developed by solutions containing couplers or other color-generating materials, emulsions of 13 the mixed-packet type, such as described in Godowsky U.S. Patent 2,698,794, issued January 4, 1955; or emulsions of the mixed-grain type, such as described in Carroll and Hanson U.S. Patent 2,592,243, issued April 8, 1952. These agents can also be used in emulsions which form latent images predominantly on the surface of the silver halide crystal or in emulsions which form latent images predominantly inside the silver halide crystal, such as those described in Davey and Knott U.S. Patent 2,592,- 250, issued April 8, 1952.

These may also be used in emulsions intended for use in difiusion transfer processes which utilize the undeveloped silver halide in the nonimage areas of the negative to form a positive by dissolving the undeveloped silver halide and precipitating it on a receiving layer in close proximity to the original silver halide emulsion layer. Such processes are described in Rott U.S. Patent 2,352,- 014, issued June 20, 1944, and Land U.S. Patents 2,584,- 029, issued January 29, 1952; 2,698,236, issued December 28, 1954 and 2,543,181, issued February 27, 1951; and Yackel et al. U.S. patent application Serial No. 586,705,

' filed May 23, 1956, now U.S. Patent 3,020,155, issued February 6, 1962. They may also be used in color transfer processes which utilize the diffusion transfer of an image-wise distribution of developer, coupler or dye, from a light-sensitive layer to a second layer, while the two layers are in close proximity to one another. Color processes of this type are described in Land U.S. Patents 2,559,643, issued July 10, 1951, and 2,698,798, issued January 4, 1955; Land and Rogers Belgian Patents 554,- 933 and 554,934, granted August 12, 1957; international Polaroid Belgian Patents 554,212, granted July 16, 1957, and 554,935, granted August 12, 1957; Yutzy U.S. Patent 2,756,142, granted July 24, 1956, and Whitmore and Mader U.S. patent application Serial No. 734,141, filed May 9, 1958.

In the preparation of the silver halide dispersions employed for preparing silver halide emulsions, there may be employed as the dispersing agent for the silver halide in its preparation, gelatin or some other colloidal material such as colloidal albumin, a cellulose derivative, or a synthetic resin, for instance, a polyvinyl compound. Some colloids which may be used are polyvinyl alcohol or a hydrolyzed polyvinyl acetate as described in Lowe U.S. Patent 2,286,215, issued June 16, 1942; a far hydrolyzed cellulose ester such as cellulose acetate hydrolyzed to an acetyl content of 1926% as described in U.S. Patent 2,327,808 of Lowe and Clark, issued August 24, 1943; a water-soluble ethanolamine cellulose acetate as described in Yutzy U.S. Patent 2,322,085, is-

sued June 15, 1943; a polyacrylamine having a combined acrylamide content of -60% and a specific viscosity of 0.251.5 on an imidized polyacrylamide of like acrylamide content and viscosity as described in Lowe, Minsk and Kenyon U.S. Patent 2,541,474, issued February 13, 1951; zein as described in Lowe U.S. Patent 2,563,791, issued August 7, 1951; a vinyl alcohol polymer containing urethane carboxylic acid groups of the type described in Unruh and Smith U.S. Patent 2,768,154, issued October 23, 1956; or containing cyano-acetyl groups such as the vinyl alcohol-vinyl cyanoacetate copolymer as described in Unruh, Smith and Priest U.S. Patent 2,808,331, issued October 1, 1957; or a polymeric material which results from polymerizing a protein or a saturated acylated protein with a monomer having'a vinyl group as described in U.S. Patent 2,852,382, of Illingsworth, Dann and Gates, issued September 16, 1958.

if desired, compatible mixtures of two or more of these colloids may be employed for dispersing the silver halide in its preparation. Combinations of these antifoggants, sensitizers, hardeners, etc., may be used.

The following examples will serve to illustrate more fully the manner of sensitizing photographic silver halide emulsions according to my invention.

An ordinary high speed bromoiodide emulsion contain- 14 ing a sensitizing dye, sulfur sensitized as described in Sheppard U.S. Patent 1,623,499 and gold sensitized in the manner illustrated in U.S. Patent 2,448,060 for example Was divided into several portions. Sulfonic acid esters and quaternary salts of tertiary amine derivatives of condensation products of alkylene oxide and certain pyranose ring products and sugar derivatives, the sensitizing compounds of my invention, were then added directly to the emulsion in the amounts indicated, in Table III. The various portions of emulsions were then coated on a transparent support such as cellulose acetate and dried. The dried coatings were exposed in an Eastman Type IB sensitorneter for A of a second and then processed for five minutes at 68 F. with good agitation in a developer of the following composition:

Water about F. (50 C.) .cc 500 Elon g 2.5 Na SO (desiccated) g 30.0 H g 2.5 Kodak balanced alkali g 10.0 KBr g 0.5 Water to make 1 liter.

The relative speed (as compared with a portion of other emulsions containing none of my sensitizers), and fog for each of the coatings were then measured. The results obtained including gamma values in some instances were as follows:

TABLE III Concen- Compound tration Relative Gamma Fog lug/mole Speed AgX Control 0 100' 1. 4o .10 4. Poly (oxyethylene) sorbitan monolaurate tris (dimethylfihydroxycthylammoniurn methane sulfonate) 0.75 148 1.20 .16 5. Poly (oxycthylene) sorbitan monolaurate tris-(triethylammonium methanesulfouate) 0.75 191 1.15 .11 6. Poly (oryethylcne) sorbitan monostearate tris (pyridinium methanesulfonate) 3. 00 276 l. 37 21 10. Sucrose octal-ris-[2-methylethyl poly (oxyethyl) triethylammoniurn methanc-sulfouate] (The oxycthylene groups of each molecule have a total molecular weight of 1320.) 3. O0 186 1.18 13 Control 0 100 i. .16 8. Sucrose octakis-[Z-methylcthyl poly (oxyetnyl) mcthanesulfonate] (The oxyethylene groups of each molecule have a total molecular Weight, of 1320.)-, i 3.0 14 9. Sucrose octakis-[2methylcthyl methanesulfonate] (The DXyBilhylene groups of each molecule have a total molecular weight The efiect of my new sensitizing compounds has been illustrated above with particular reference to ordinary high speed photographic silver bromoiodide emulsions, although it is to be understood that other silver halide emulsions can be employed to less advantage. My sensitizers can be used in emulsions which are acidic in character or in emulsions which are alkaline. When adding my sensitizers to such emulsions it is generally desirable to adjust the pH of the sensitizing solution so that it will not seriously alter the pH of the emulsion to be treated.

The invention has been described in detail with particular reference to preferred embodiments thereof but it Will be understood that variations and modifications can be effected Within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

What I claim as my invention and desire secured by Letters Patent of the United States'is:

1. A photographic silver halide emulsion containing a condensation product of alkylene oxides and products containing the pyranose ring system selected from the class consisting of the sulfonic acid esters, pyridinium salts, and quaternary ammonium salts of the said condensation products of alkylene oxides and products containing the pyranose ring system.

2. A photographic silver halide emulsion sensitized with (1) a gold compound, (2) a compound containing a labile sulfur atom, and (3) a condensation product of alkylene oxides and products containing the pyranose ring system selected from the class consisting of the sulionic acid esters, pyridinium salts, and quaternary ammonium salts of the said condensation products of alkylene oxides and products containing the pyranose ring system.

3. A photographic silver halide emulsion containing a compound selected from the class consisting of compounds having the formula:

wherein X is a member selected from the class consisting of sulfonic ester radicals, pyridinium radicals and ammonium radicals; n I2 and 21 each represent a positive integer of at least 1 such that the sum of n +n +n is an integer of from 8 to 680; m and m are each positive integers of from 1 to 18 such that the sum of m-l-m is an integer of from 4 to 20; and d is a positive integer of 1 to 2.

4. A photographic silver halide emulsion containing a compound selected from the class consisting of compounds having the formula:

wherein the Zs represent a 2 2) n' d1' m-1 member selected from the class consisting of lower alkyl sulfonate radicals having from 1 to 4 carbon atoms, an arene sulfonate radical, a pyridinium radical and an ammonium group; Y is an anion selected from the class consisting of lower alkyl sulfonate ions having from 1 to 4 carbon atoms, an arene sulfonate ion, a perchlorate ion and a halide ion; and m is the integer of l and 2 such that when X is a sulfonate group, m is 1 and when X is a pyridinium radical or an ammonium radical m is 2.

5. A photographic silver halide emulsion containing the compound poly(oxyethylene)sorbitan monostearate tris (pyridinium methanesulfonate) 6. A photographic silver halide emulsion containing the compound sucrose octakis-[Z-methylethyl poly(oxyethyl)pyridinium methanesulfonate] said compound containing oxyethylene groups having a total molecular weight of 1320 'per molecule.

7. A photographic silver halide emulsion containing the compound poly(oxyethylene)sorbitan monolaurate tris- (triethylammonium methanesulfonate). I

8. A photographic silver halide emulsion containing the compound sucrose octakis-[Z-methyl ethyl poly(oxyethyl) triethylammonium methanesulfonate], said compound containing oxyethylene groups having a total molecular weight of 1320 per molecule.

9. A photographic silver halide emulsion containing the compound poly(oxyethylene) sorbitan monolaurate tris- (dimethyl-B-hydroxyethylammonium methanesulfonate).

References Cited in the file of this patent UNITED STATES PATENTS 2,400,532 Blake et al May 21, 1946 

2. A PHOTOGRAPHIC SILVER HALIDE EMULSION SENSITIZED WITH (1) A GOLD COMPOUND, (2) A COMPOUND CONTAINING A LABILE SULFUR ATOM, AND (3) A CONDENSATION PRODUCT OF ALKYLENE OXIDES AND PRODUCTS CONTAINING THE PYRANOSE RING SYSTEM SELECTED FROM THE CLASS CONSISTING OF THE SULFONIC ACID ESTERS, PYRIDINIUM SALTS, AND QUATERNARY AMONIUM SALTS OF THE SAID CONDENSATION PRODUCTS OF ALKYLENE OXIDES AND PRODUCTS CONTAINING THE PYRANOSE RING SYSTEM. 